Clinical significance of sperm DNA damage in assisted reproduction outcome

Background: Sperm DNA damage shows great promise as a biomarker of infertility. The study aim is to determine the usefulness of DNA fragmentation (DF), including modified bases (MB), to predict assisted reproduction treatment (ART) outcomes. Methods: DF in 360 couples (230 IVF and 130 ICSI) was measured by the alkaline Comet assay in semen and in sperm following density gradient centrifugation (DGC) and compared with fertilization rate (FR), embryo cumulative scores (ECS1) for the total number of embryos/treatment, embryos transferred (ECS2), clinical pregnancy (CP) and spontaneous pregnancy loss. MB were also measured using formamidopyrimidine DNA glycosylase to convert them into strand breaks. Results: In IVF, FR and ECS decreased as DF increased in both semen and DGC sperm, and couples who failed to achieve a CP had higher DF than successful couples (+12.2 semen, P = 0.004; +9.9 DGC sperm, P = 0.010). When MB were added to existing strand breaks, total DF was markedly higher (+17.1 semen, P = 0.009 and +13.8 DGC sperm, P = 0.045). DF was not associated with FR, ECS or CP in either semen or DGC sperm following ISCI. In contrast, by including MB, there was significantly more DNA damage (+16.8 semen, P = 0.008 and +15.5 DGC sperm, P = 0.024) in the group who did not achieve CP. Conclusion: SDF can predict ART outcome for IVF. Converting MB into further DNA strand breaks increased the test sensitivity, giving negative correlations between DF and CP for ICSI as well as IVF. © 2010 The Author.

Relationships between human sperm protamines, DNA damage and assisted reproduction outcomes

The exchange of histones with protamines in sperm DNA results in sperm chromatin compaction and protection. Variations in sperm protamine expression are associated with male infertility. The aim of this study was to investigate relationships between DNA fragmentation, sperm protamines and assisted reproduction treatment. Semen and spermatozoa prepared by density-gradient centrifugation (DGC) from 73 men undergoing IVF and 24 men undergoing intracytoplasmic sperm injection (ICSI) were included in the study. Nuclear DNA fragmentation was assessed using the alkaline Comet assay and protamines were separated by acid-urea polyacrylamide gels. Sperm DNA fragmentation and protamine content (P1-DNA, P2-DNA, P1 + P2-DNA) decreased in spermatozoa after DGC. Abnormally high and low P1/P2 ratios were associated with increased sperm DNA fragmentation. Couples with idiopathic infertility had abnormally high P1/P2 ratios. Fertilization rates and embryo quality decreased as sperm DNA fragmentation or protamines increased. Sperm DNA fragmentation was lower in couples achieving pregnancies after IVF, but not after ICSI. There was no correlation between protamine content (P1-DNA, P2-DNA, P1 + P2-DNA) or P1/P2 ratios and IVF or ICSI pregnancies. Increased sperm DNA fragmentation was associated with abnormal protamination and resulted in lower fertilization rates, poorer embryo quality and reduced pregnancy rates. During late spermatogenesis, around 85% of the histones in the sperm nucleus are replaced with protamines. This process results in sperm chromatin compaction and also transcription silencing. In the human, protamines are comprised of two types: protamine-1 (P1) and protamine-2 (P2). Variations in sperm protamine expression are associated with male infertility. Similarly, sperm DNA integrity is important for male fertility. The aim of this study was to investigate relationships between DNA fragmentation, sperm protamines and assisted reproduction treatment. Semen and spermatozoa prepared by density-gradient centrifugation (DGC) from 73 men undergoing IVF and 24 men undergoing intracytoplasmic sperm injection (ICSI) were included in the study. Nuclear DNA fragmentation was assessed using the alkaline Comet assay and protamines were separated by acid-urea polyacrylamide gels. Sperm DNA fragmentation and protamine content decreased in spermatozoa after DGC. Abnormally high and low P1/P2 ratios were associated with increased sperm DNA fragmentation. Couples with idiopathic infertility had abnormally high P1/P2 ratios. Fertilization rates and embryo quality decreased as sperm DNA fragmentation or protamines increased. Sperm DNA fragmentation was lower in couples achieving pregnancies after IVF, but not after ICSI. There was no correlation between protamine content or P1/P2 ratios and IVF or ICSI pregnancies. Increased sperm DNA fragmentation was associated with abnormal protamination and resulted in lower fertilization rates, poorer embryo quality and reduced pregnancy rates.

An algorithm to predict pregnancy in assisted conception

BACKGROUND: Male fertility potential cannot be measured by conventional parameters for assisted reproduction by intracytoplasmic sperm injection. This study determines the relationship between testicular and ejaculated sperm mitochondrial (mt) DNA deletions, nuclear (n) DNA fragmentation and fertilisation and pregnancy rates in ICSI. METHODS: Ejaculated sperm were obtained from 77 men and testicular sperm from 28 men with obstructive azoospermia undergoing ICSI. Testicular sperm were retrieved using a Trucut needle. MtDNA analysed using a long polymerase chain reaction. The alkaline Comet assay determined nDNA fragmentation. RESULTS: Of subjects who achieved a pregnancy (50%) using testicular sperm, only 26% had partners�??�?�¢?? sperm with wild type (WT) mtDNA. Of pregnant subjects (38%) using ejaculated sperm, only 8% had partner sperm with WT mtDNA.. In each, the successful group had less mtDNA deletions and less nDNA fragmentation. There were inverse relationships between pregnancy and mtDNA deletion numbers, size and nDNA fragmentation for both testicular and ejaculated sperm. No relationships were observed with fertilisation rates. An algorithm for the prediction of pregnancy is presented based on the quality of sperm nDNA and mtDNA. CONCLUSION: In both testicular and ejaculated sperm, mtDNA deletions and nDNA fragmentation are closely associated with pregnancy in ICSI.

The impact of sperm DNA damage in assisted conception and beyond: recent advances in diagnosis and treatment

Abstract Sperm DNA damage is a useful biomarker for male infertility diagnosis and prediction of assisted reproduction outcomes.
It is associated with reduced fertilization rates, embryo quality and pregnancy rates, and higher rates of spontaneous miscarriage
and childhood diseases. This review provides a synopsis of the most recent studies from each of the authors, all of whom have major
track records in the field of sperm DNA damage in the clinical setting. It explores current laboratory tests and the accumulating body
of knowledge concerning the relationship between sperm DNA damage and clinical outcomes. The paper proceeds to discuss the
strengths, weaknesses and clinical applicability of current sperm DNA tests. Next, the biological significance of DNA damage in
the male germ line is considered. Finally, as sperm DNA damage is often the result of oxidative stress in the male reproductive tract,
the potential contribution of antioxidant therapy in the clinical management of this condition is discussed. DNA damage in human spermatozoa is an important attribute of semen quality. It should be part of the clinical work up and properly controlled trials
addressing the effectiveness of antioxidant therapy should be undertaken as a matter of urgency.

Sperm DNA damage has a negative association with live birth rates after IVF.

Sperm DNA damage has a negative impact on pregnancy rates following assisted reproduction treatment (ART). The aim of the present study was to examine the relationship between sperm DNA fragmentation and live-birth rates after IVF and intracytoplasmic sperm injection (ICSI). The alkaline Comet assay was employed to measure sperm DNA fragmentation in native semen and in spermatozoa following density-gradient centrifugation in semen samples from 203 couples undergoing IVF and 136 couples undergoing ICSI. Men were divided into groups according to sperm DNA damage. Following IVF, couples with <25% sperm DNA fragmentation had a live-birth rate of 33%; in contrast, couples with >50% sperm DNA fragmentation had a much lower live-birth rate of 13%. Following ICSI, no significant differences in sperm DNA damage were found between any groups of patients. Sperm DNA damage was also associated with low live-birth rates following IVF in both men and couples with idiopathic infertility: 39% of couples and 41% of men with idiopathic infertility have high sperm DNA damage. Sperm DNA damage assessed by the Comet assay has a close inverse relationship with live-birth rates after IVF.

Sperm DNA damage has a negative impact on assisted reproduction treatment outcome, in particular, on pregnancy rates. The aim of the present study was to examine the relationship between sperm DNA fragmentation and live-birth rates after IVF and intracytoplasmic sperm injection (ICSI). The alkaline Comet assay was employed to measure sperm DNA fragmentation in native semen and in spermatozoa following density-gradient centrifugation in semen samples from 203 couples undergoing IVF and 136 couples undergoing ICSI. Men were divided into groups according to sperm DNA damage and treatment outcome. Following IVF, couples with <25% sperm DNA fragmentation had a live birth rate of 33%. In contrast, couples with >50% sperm DNA fragmentation had a much lower live-birth rate of 13% following IVF. Following ICSI, there were no significant differences in levels of sperm DNA damage between any groups of patients. Sperm DNA damage was also associated with the very low live-birth rates following IVF in both men and couples with idiopathic infertility: 39% of couples and 41% of men have high level of sperm DNA damage. Sperm DNA damage assessed by the Comet assay has a close inverse relationship with live-birth rates after IVF.

Where are all the men? The marginalization of men in social scientific research on infertility

There is a wealth of research exploring the psychological consequences of infertility and assisted reproduction technology: a substantial body of sociological and anthropological work on ‘reproductive disruptions’ of many kinds and a small but growing literature on patient perspectives of the quality of care in assisted reproduction. In all these fields, research studies are far more likely to be focused on the understandings and experiences of women than those of men. This paper discusses reasons for the relative exclusion of men in what has been called the ‘psycho-social’ literature on infertility, comments on research on men from psychological and social perspectives and recent work on the quality of patient care, and makes suggestions for a reframing of the research agenda on men and assisted reproduction. Further research is needed in all areas, including: perceptions of infertility and infertility treatment seeking; experiences of treatment; information and support needs; decisions to end treatment; fatherhood post assisted conception; and the motivation and experiences of sperm donors and men who seek fatherhood through surrogacy or co-parenting. This paper argues for multimethod, interdisciplinary research that includes broader populations of men which can contribute to improved clinical practice and support for users of assisted reproduction treatment

Effects of vasectomy on spermatogenesis and fertility outcomes after assisted conception

Abstract BACKGROUND: Each year 40,000 men have a vasectomy in the UK whilst another 2400 request a reversal to begin a second family. Sperm can now be obtained by testicular biopsy and subsequently used in assisted conception with intracytoplasmic sperm injection (ICSI). The study aims were to compare sperm yields of men post-vasectomy or with obstructive azoospermia (OA) of unknown aetiology with fertile men and to assess any alteration in the clinical pregnancy rates after ICSI. METHODS: Testicular tissue was obtained by Trucut needle from men who had undergone a vasectomy >5yrs previously, had OA from other causes and from fertile men during vasectomy. Seminiferous tubules were milked to measure sperm yields. Numbers of Sertoli cells, spermatids and thickness of the seminiferous tubule walls were assessed using quantitative computerized analysis. RESULTS and CONCLUSIONS: Sperm yields/g testis were significantly decreased in men post-vasectomy and in men with OA, relative to fertile men. Significant reductions were also observed in early (40%) and mature (29%) spermatid numbers and an increase of 31% was seen in the seminiferous tubule wall (basal membrane and collagen thickness) of vasectomised men compared to fertile men. Clinical pregnancy rates in couples who had had a vasectomy were also significantly reduced.

The Role of Tool/Sheet Contact in Plug-Assisted Thermoforming.

Plug-assisted thermoforming produces a wide range of polymer products through a combination of deformation by air pressure and contact with tool surfaces. In this paper the role of tool/sheet contact in determining the process output is investigated. A combination of thermoforming, friction and heat transfer tests were carried out on common tool and sheet materials. The results show that the typical friction coefficients for the material combinations are within the range 0.1 to 0.3, but the values rise sharply on approaching thermoforming temperatures. Thermal imaging tests demonstrate that all of the plug materials significantly cool the heated sheet on contact, even over very short periods of time. The temperature of the plug is very important. At low plug temperatures heat transfer effects predominate, whereas at high plug temperatures friction effects predominate. A plug temperature of approximately 100oC balances these effects and creates the most effective material distribution.

Abortion and Nation: The Politics of Reproduction in Contemporary Ireland

Abortion politics are contentious and divisive in many parts of the world, but nowhere more so than in Ireland. Abortion and Nation examines the connection between abortion politics and hegemonic struggles over national identity and the nation-state in the Irish Republic. Situating the abortion question in the global context of human rights politics, as well as international social movements, Lisa Smyth analyses the formation and transformation of abortion politics in Ireland from the early 1980s to the present day. She considers whether or not the shifting connections between morality, rights and nationhood promise a new era of gender equality in the context of nation-state citizenship.
The book provides a new sociological framework through which the significance of conflict over abortion and reproductive freedom is connected to conflict over national identity. It also offers a distinctive in-depth consideration of the connection between gender and nationhood, particularly in terms of its impact on women's status as citizens; within the nation-state; within the European Union; and as members of a global civil society.